body {
  padding-top: 50px;
}

td {
  padding-left: 0;
}

td button {
  width: 50%;
}

.sub-header {
  padding-bottom: 10px;
  border-bottom: 1px solid #eee;
}

.navbar-fixed-top {
  border: 0;
}

.sidebar {
  display: none;
}

@media (min-width: 768px) {
  .sidebar {
    position: fixed;
    top: 51px;
    bottom: 0;
    left: 0;
    z-index: 1000;
    display: block;
    padding: 20px;
    overflow-x: hidden;
    overflow-y: auto;
    background-color: #f5f5f5;
    border-right: 1px solid #eee;
  }
}

.nav-sidebar {
  margin-right: -21px;
  margin-bottom: 20px;
  margin-left: -20px;
}

.nav-sidebar>li>a {
  padding-right: 20px;
  padding-left: 20px;
}

.nav-sidebar>.active>a,
.nav-sidebar>.active>a:hover,
.nav-sidebar>.active>a:focus {
  color: #fff;
  background-color: #428bca;
}

.main {
  padding: 20px;
}

@media (min-width: 768px) {
  .main {
    padding-right: 40px;
    padding-left: 40px;
  }
}

.main.page-header {
  margin-top: 0;
}

.placeholders {
  margin-bottom: 30px;
  text-align: center;
}

.placeholders h4 {
  margin-bottom: 0;
}

.placeholder {
  margin-bottom: 20px;
  display: inline-block;
  width: 30%;
  margin-right: 2%;
}

.placeholder:last-child {
  margin-right: 0;
}

.placeholder img {
  display: block;
  border-radius: 100%;
  width: 200px;
  height: 200px;
  object-fit: cover;
}

.login-register-container {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  background-color: #e6f7ff;
}

.login-register-link {
  text-decoration: none;
  color: black;
}

.login-form,
.register-form {
  width: 400px;
  background-color: white;
  padding: 20px;
  border-radius: 5px;
  box-shadow: 0 0 5px rgba(0, 0, 0, 0.2);
}

/* 以下是新增样式，用于扩大表单内元素的间距等 */
.input-lg {
  font-size: 1.3em;
  padding: 15px;
}

.btn-lg {
  font-size: 1.3em;
  padding: 10px 20px;
}

.text-center {
  text-align: center;
}